1. Field of the Invention
The present invention relates to a program correcting device and program correcting method for correcting an operating program of an industrial robot.
2. Description of the Related Art
In recent years, industrial robots such as vertical multi-articulated robots have been used for laser cutting, arc welding, deburring, and various other applications. Control devices of these robots execute operating programs which are prepared in advance so as to move tools which are attached to the robots (for example, laser oscillators for laser cutting) at command speeds. However, if the movement path of a tool includes a corner, the movement speed is unavoidably reduced from the command speed while the tool passes the corner. In particular, when the amount of reduction of the movement speed is large, the processing quality on a workpiece is liable to fall during the period when the tool passes the corner. For example, movement speed of the tool which is greatly lower than the command speed may result in excessive processing on the workpiece.
In relation to this, JP H11-39021A proposes a method of interpolation of a robot motion path, comprising rotating a wrist flange so that an intersecting point of a drive axis of the wrist flange and a teaching plane moves along a predetermined arc if the distance from a control point which is set on the tip of the tool to a corner becomes smaller than a predetermined reference distance. According to the method of interpolation of a path in JP H11-39021A, the wrist flange is rotated smoothly rotate so that the control point is linearly moved on the teaching plane, and therefore it is possible to prevent the movement speed from reducing while the control point passes the corner. However, if the method of interpolation of a path in JP H11-39021A is employed, it is necessary to orient the flange surface of the wrist flange to which the tool is mounted, to be parallel to the teaching plane. In order to orient the wrist flange in this way, it is necessary to change the hardware settings of the robot in detail, and a user would find it difficult to change such settings.
A device and method which can reduce the drop in speed of the tip of a tool without changing the hardware settings of the robot have been sought.